package exer;

public class Thread_2252 {

 private static volatile int COUNTER = 0;
   private static Object lock = new Object();
 
    public static void main(String[] args) {
        // 创建三个线程，并指定线程名，每个线程名分别用A,B,C表示
        Thread t1 = new Thread(() -> {
            // 循环10次
            for (int i = 0; i < 10; i++) {
                // 执行的代码加锁
                synchronized (lock) {
                    // 每次唤醒后都重新判断是否满足条件// 每条线程判断的条件不一样，注意线程t1,t2while (COUNTER % 3 != 0) {

                            while(COUNTER%3!=0){
                                try {

                                    // 不满足输出条件时，主动等待并释放锁
                                    lock.wait();
                                } catch (InterruptedException e) {
                                    e.printStackTrace();
                                }
                            }

                    System.out.print(Thread.currentThread().getName());
                    // 累加计数
                    COUNTER++;
                    // 唤醒其他线程
                    lock.notifyAll();
                }
                }
            }, "A");
 
        Thread t2 = new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                synchronized (lock) {
                    while (COUNTER % 3 != 1) {
                        try {
                            lock.wait();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                    System.out.print(Thread.currentThread().getName());
                    COUNTER++;
                    lock.notifyAll();
                }
            }
        }, "B");
 
        Thread t3 = new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                synchronized (lock) {
                    while (COUNTER % 3 != 2) {
                        try {
                            lock.wait();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
 
                   System.out.println(Thread.currentThread().getName());
                    COUNTER++;
                    lock.notifyAll();
                }
            }
        }, "C");
 
        // 启动线程
        t1.start();
        t2.start();
        t3.start();
    }
}